1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "compat.h"
18 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 
23 #include "parser.h"
24 #include "utils.h"
25 
26 struct gm_selector {
27 	char		 type;
28 	const char	*ds;
29 	const char	*selector;
30 	const char	*addr;
31 	const char	*port;
32 };
33 
34 static void	gm_parse_selector(char *, struct gm_selector *);
35 
36 static int	gm_parse(struct parser *, const char *, size_t);
37 static int	gm_foreach_line(struct parser *, const char *, size_t);
38 static int	gm_free(struct parser *);
39 
40 void
41 gophermap_initparser(struct parser *p)
42 {
43 	memset(p, 0, sizeof(*p));
44 
45 	p->name = "gophermap";
46 	p->parse = &gm_parse;
47 	p->free = &gm_free;
48 
49 	TAILQ_INIT(&p->head);
50 }
51 
52 static void
53 gm_parse_selector(char *line, struct gm_selector *s)
54 {
55 	s->type = *line++;
56 	s->ds = line;
57 	s->selector = "";
58 	s->addr = "";
59 	s->port = "";
60 
61 	if ((line = strchr(line, '\t')) == NULL)
62 		return;
63 	*line++ = '\0';
64 	s->selector = line;
65 
66 	if ((line = strchr(line, '\t')) == NULL)
67 		return;
68 	*line++ = '\0';
69 	s->addr = line;
70 
71 	if ((line = strchr(line, '\t')) == NULL)
72 		return;
73 	*line++ = '\0';
74 	s->port = line;
75 }
76 
77 static int
78 gm_parse(struct parser *p, const char *buf, size_t size)
79 {
80 	return parser_foreach_line(p, buf, size, gm_foreach_line);
81 }
82 
83 static inline int
84 emit_line(struct parser *p, enum line_type type, struct gm_selector *s)
85 {
86 	struct line *l;
87 	char buf[LINE_MAX], b[2] = {0};
88 
89 	if ((l = calloc(1, sizeof(*l))) == NULL)
90 		goto err;
91 
92 	if ((l->line = strdup(s->ds)) == NULL)
93 		goto err;
94 
95 	switch (l->type = type) {
96 	case LINE_LINK:
97 		if (s->type == 'h' && has_prefix(s->selector, "URL:")) {
98 			strlcpy(buf, s->selector+4, sizeof(buf));
99 		} else {
100 			strlcpy(buf, "gopher://", sizeof(buf));
101 			strlcat(buf, s->addr, sizeof(buf));
102 			strlcat(buf, ":", sizeof(buf));
103 			strlcat(buf, s->port, sizeof(buf));
104 			strlcat(buf, "/", sizeof(buf));
105 			b[0] = s->type;
106 			strlcat(buf, b, sizeof(buf));
107 			if (*s->selector != '/')
108 				strlcat(buf, "/", sizeof(buf));
109 			strlcat(buf, s->selector, sizeof(buf));
110 		}
111 
112 		if ((l->alt = strdup(buf)) == NULL)
113 			goto err;
114 		break;
115 
116 	default:
117 		break;
118 	}
119 
120 	TAILQ_INSERT_TAIL(&p->head, l, lines);
121 
122 	return 1;
123 
124 err:
125 	if (l != NULL) {
126 		free(l->line);
127 		free(l->alt);
128 		free(l);
129 	}
130 	return 0;
131 }
132 
133 static int
134 gm_foreach_line(struct parser *p, const char *line, size_t linelen)
135 {
136 	char buf[LINE_MAX] = {0};
137 	struct gm_selector s = {0};
138 
139 	memcpy(buf, line, MIN(sizeof(buf)-1, linelen));
140 	gm_parse_selector(buf, &s);
141 
142 	switch (s.type) {
143 	case '0':	/* text file */
144 	case '1':	/* gopher submenu */
145 	case '2':	/* CCSO nameserver */
146 	case '4':	/* binhex-encoded file */
147 	case '5':	/* DOS file */
148 	case '6':	/* uuencoded file */
149 	case '7':	/* full-text search */
150 	case '8':	/* telnet */
151 	case '9':	/* binary file */
152 	case '+':	/* mirror or alternate server */
153 	case 'g':	/* gif */
154 	case 'I':	/* image */
155 	case 'T':	/* telnet 3270 */
156 	case ':':	/* gopher+: bitmap image */
157 	case ';':	/* gopher+: movie file */
158 	case 'd':	/* non-canonical: doc */
159 	case 'h':	/* non-canonical: html file */
160 	case 's':	/* non-canonical: sound file */
161 		if (!emit_line(p, LINE_LINK, &s))
162 			return 0;
163 		break;
164 
165 		break;
166 
167 	case 'i':	/* non-canonical: message */
168 		if (!emit_line(p, LINE_TEXT, &s))
169 			return 0;
170 		break;
171 
172 	case '3':	/* error code */
173 		if (!emit_line(p, LINE_QUOTE, &s))
174 			return 0;
175 		break;
176 	}
177 
178 	return 1;
179 }
180 
181 static int
182 gm_free(struct parser *p)
183 {
184 	/* flush the buffer */
185 	if (p->len != 0)
186 		gm_foreach_line(p, p->buf, p->len);
187 
188 	free(p->buf);
189 
190 	return 1;
191 }